Umpires need Mentors. Here are 100 of the World's Best. One of the best ways for baseball umpires to improve is to learn from mentors. Veteran umpire Kent Walker contacted 100 of the best umpire mentors in the world and asked them to provide advice any umpire could benefit from. Through answers to 9 key questions about the finer details of umpiring, he shares their secrets and tips on how you can become a better umpire - whether you're a beginning Little League umpire, a seasoned College umpire, or even a pro!